In the movie business that uses recording media, there is a sales strategy whereby a digitized movie work and an application for online shopping are sold recorded on a same recording medium. The creator has an expectation that by incorporating a mechanism for selling character goods relating to the movie work online on the one recording medium, the synergy effect of the movie work and the application will increase sales of the character goods. To realize such contents, there is a desire that upcoming recording media and playback apparatuses be equipped with an application execution environment that has a greater degree of freedom.
In order to realize simultaneous execution of such a movie work and online shopping application, a technique is required to execute the application in accordance with playback of digital video. One known technique for executing Java applications is “signaling” set forth in the DVD-MHP specification. Signaling involves defining, on a playback time axis of a digital stream, a start point at which the application is to be run and an end point at which the application is to be terminated, transmitting information called an AIT (application information table) at this point, and causing the playback apparatus to perform control in accordance with this AIT.
However, regression of the playback time axis may occur in the procession of playback. This means that playback proceeds in the reverse direction of the time axis due to Backward play. If regression and progression back and forth of the content is repeated with the point at which the application should be run and the point at which the application should be terminated being reversed, loading and discarding to and from the work memory will also be performed numerous times, thus causing and excessive load for reading.